1. Field of the Invention
This invention relates to interactive computer systems, and more particularly to such systems capable of transforming digitally encoded speech data segments into understandable speech. The invention is relevant to the field of computer-assisted instruction.
2. Description of the Prior Art
Digital speech processors that can operate in parallel with a programmable digital computer have come into wide spread use in recent years. An excellent example is the "Solid State Speech" (trademark) synthesizer that is widely used as an accessory for the Texas Instruments TI99/4A home computer. This system includes a synthesizer chip which can accept from the computer a stream of data that defines the individual phonemes of a spoken message. The message must be presented to the synthesizer at a controlled rate of speed and with relatively continuous active involvement of the computer in the speech generation process.
An alternative arrangement is disclosed in U.S. Pat. No. 4,335,277 which issued on June 15, 1982 to Ajay K. Puri. A read-only memory (12A and 12B in FIG. 2 of the patent) containing a plurality of variable length, digitally-encoded speech data segments is connected to a synthesizer chip that is connected in turn to a computer. The computer can initiate the conversion of an entire single data segment into speech by passing the address of the desired segment to the read-only memory and then starting the synthesizer chip to speak from that address onward. In this manner, a single speech segment may be generated in response to a single request from the computer, with no further computer intervention.